1. Field of the Invention
The present invention relates to an image recording device, an image defect detection device, and an image defect detection method, and particularly, to an image processing technology for performing a high-accuracy image defect detection process within a certain time.
2. Description of the Related Art
Since it is necessary for a process of detecting an image defect such as a streak of a printed material to be caused to end within a predetermined time for a printed material which is printed at regular time intervals, and for a detection process for the next printed material to be prepared, it is necessary to end the process in a short time. Further, it is conceivable to use a calculation device having a high-speed processing capability in order to end a detection process in a short time, but there is a problem in that a device cost increases.
For such a first problem, JP2011-137736A describes a technology for setting a determination region in a square shape of 3×3 pixels for first image data that is original print data and second image data obtained by reading a printed material printed on the basis of the first image data, performing a first comparison determination of a pixel value for each pixel, and performing a second comparison determination using pixels not used in the first comparison determination for a determination region in which the number of pixels determined to be defective print pixels is within a certain range with respect to the determination region. According to the technology described in JP2011-137736A, it is possible to speed up a test process for a printed material.
Further, a process of detecting an image defect for a determination of pass and fail of a printed material is performed according to a detection condition set in advance. Therefore, the number of sheets insufficient due to failure is empirically determined in advance, the number of sheets required for output is increased, and print is performed. However, if detection conditions are too severe, the number of fail sheets increases and the number of pass sheets is insufficient. Accordingly, it is necessary for the number of sheets to be added to further increase for the number of sheets required for output. On the other hand, if the detection condition is too loose, there is a problem in that surplus print is caused and productivity is degraded.
For such a second problem, JP2009-133741A describes a technology for setting a high level of a criterion of good and bad in all regions and a slightly defective portion can be detected for all the regions in a case where high-accuracy printing is required, and increasing a level of the criterion of good and bad of a surface on which a product name is printed in the case of a packaging box of sweets or the like and decreasing the level of the criterion of good and bad for a region difficult to view from the outside due to gluing in a box body.